In the process of achieving cold shutdown following the shutdown of Hamaoka Nuclear Power Station Unit 5 on May 14, 2011, the readings of conductivity meters monitoring the purity of the water in the main condensers began to rise, and the conductivity of the water in the reactor also began to rise. After cold shutdown, investigation identified that a high volume of sea water had flowed into the reactor facility due to damage to the main condenser tubes. Evaluations focusing on corrosion of materials have b...
英字タイトル:
Effect of sea water intrusion from main condenser, damaged by breakon reactor core internals, Hamaoka Unit 5

As use of condition-based maintenance is allowed in the new regulatory inspection system employed in Japan's nuclear pow er plants in 2009, development of advanced diagnostic technologies for motor-operated valves (MOVs) is now required. This report discusses advanced technologies in valve-setup verification, valve performance evaluation, monitoring of valve/ac tuator conditions by performance diagnostic system and moreover detection of stem crack by ultrasonic diagnostic system....
英字タイトル:
Development of Advanced Diagnostic Technologies for Motor-operated Valves